#!/usr/bin/env ruby

# Source: https://github.com/cmur2/munin-bitcoin

#
# Example usage:
#  Do
#    ln -s /path/to/bitcoin_ bitcoin_<currency>
#  where <currency> is a currency known to https://api.bitcoinaverage.com/ticker/
#  like EUR or USD.
#
# Example config:
#  [bitcoin_*]
#

require 'rubygems'
require 'json'

require 'open-uri'

script = File.basename($0)
@currency = script.gsub('bitcoin_', '')
@cmd = ARGV[0]

# open stderr
$stderr = IO.new(2, "w")

def uri(currency)
	"https://apiv2.bitcoinaverage.com/indices/global/ticker/BTC#{currency}"
end

def echo_price(currency, &get_data)
	case @cmd
	when 'config'
		puts "graph_title Bitcoin (in #{currency})"
		puts "graph_args --lower-limit 0"
		puts "graph_vlabel #{currency}"
		puts "graph_category finance"
		puts "graph_scale no"
		puts "graph_info This graph shows the last price of Bitcoin from http://bitcoinaverage.com/"
		%w{last ask bid total_vol 24h_avg}.each do |x|
			puts "#{x}.label #{x.gsub('_', ' ').split(' ').map { |y| y.capitalize }.join(' ')}"
			puts "#{x}.type GAUGE"
		end
	else
		data = get_data.call
		%w{last ask bid total_vol 24h_avg}.each do |x|
			puts "#{x}.value #{data[x]}"
		end
	end
end

begin
	echo_price(@currency) do
		raw_data = open(uri(@currency)).read
		data = JSON.parse(raw_data)
		#puts data.inspect
		data
	end
rescue => ex
	$stderr.puts "Cannot connect to bitcoinaverage.com: #{ex.to_s}"
end